We have been successful in selecting for sublines of the TA3-Ha mammary adenocarcinoma with the property of implanting in multiple organs, beyond the lungs, following intravenous (tail vein) injection. We will continue these selective passages emphasizing the particular site of metastasis. We will then compare the plasma membranes of these metastasizing variants with the original TA3-Ha subline, which gives predominantly lung implantation, in order to correlate the metastatic patterns with cell surface components. We hope to learn whether there are specific components of the membrane which are crucial for widespread metastasis.